It is known that an acrylic ester and a methacrylic ester each having an adamantane skeleton can be polymerized into a polymer which is excellent in heat resistance, mechanical strength such as impact resistance and surface hardness and optical characteristics. For instance, Japanese Patent Laid-Open Application {No. 307844/1988 (Showa 63)} proposes a diacrylate and dimethacrylate having a halogen atom or a hydroky group at each of the 5-position of the adamantane skeleton or at each of the 7-position of the same. The acrylic ester and methacrylic ester each having the above-mentioned structural unit, which are colorless and transparent and have high a surface hardness and also large refractive index, are highly useful as a raw material for optical instruments and members such as lens, prisms, photosensitive materials, optical fiber and optical discs. In addition, the acrylic ester and methacrylic ester as mentioned above have each a surpassingly high melting point and surface hardness as compared with the acrylic ester and methacrylic ester that are being generally used, are highly useful as a material of a heat resistant covering and forming for an acrylic ester and methacrylic ester. However the aforesaid useful acrylic ester and methacrylic ester suffer from a disadvantage of insufficient transparency in a low wavelength region.
As mentioned hereinbefore, the acrylic ester and a methacrylic ester each having an adamantane skeleton which is imparted with a specific chemical structure are highly useful as a raw material for a functional resin. However it is desired to develop an acrylic ester and a methacrylic ester which have any of various chemical structures and which are capable of being made into an acrylic ester and a methacrylic ester, respectively that are enhanced in such functionality as optical properties and heat resistance.